FIG. 1 is a diagram illustrating a slot for RACH (Random Access Channel) (Access Slot) and a slot for SCH (Shared Channel) (Time Slot) defined in a W-CDMA (Wideband Code Division Multiple Access) system. For both slots, one frame is 10 [msec]. The access slot uses a portion resulting from dividing two frames into 14 portions as a transmission unit for RACH. On the other hand, the time slot uses a portion resulting from dividing one frame into 14 portions as a transmission unit for SCH. Therefore, the transmission unit for RACH is twice as long as SCH.
The access slot and time slot operate in parallel temporally. That is, RACH and SCH may be received simultaneously by a base station apparatus. However, since the 3G (third-generation) adopts the CDMA scheme, and RACH and SCH are spectrum-spread with spread codes which are orthogonal to each other, the base station apparatus can demodulate RACH and SCH.
On the other hand, the 3GPP Long Term Evolution (hereinafter referred to as “LTE”) is currently studying about a base station apparatus having a wide range communicable area (coverage). When the base station apparatus secures a wide range coverage, a timing of receiving a signal transmitted from each terminal apparatus significantly differs from each other, depending on the positional relationship between the base station apparatus and each terminal apparatus. For example, the propagation delay of a terminal apparatus located in the vicinity of a base station apparatus decreases because the distance between the base station apparatus and the terminal apparatus is small. On the other hand, the propagation delay of a terminal apparatus located at an end point (cell edge) of the communicable area increases because the distance between the base station apparatus and the terminal apparatus is large.
According to the LTE, a base station can control transmission timing of a terminal apparatus arbitrarily by using a time alignment function. And therefore, regarding a channel transmitted from a terminal apparatus after a connection between the base station apparatus and the terminal apparatus is established, i.e. PUSCH (Physical Uplink Shared Channel) and PUCCH (Physical Uplink Control Channel), differences in propagation delays among terminal apparatuses are not considerable.    Non-Patent Document 1: TS25.211 pp. 13-15